Expansible elevator plug



Jan. 6, 1953 c. R. MURPHY EXPANSIBLE E ILEVATOR PLUG Filed Feb. 25, 1950Fig Fig.2

67000;! R, Murphy 'INVENTOR. v

BY Q M m,

Patented Jan. 6, 1953 EXPANSIBLE ELEVATOR- PLUG Olauast R. Murphy,Amarillo, Tex., assignor of one-half to Lee Murphy, Plainview, Tex.

Application February 23, 1950, Serial No. 145,647

1 Claim.

This invention relates to new and useful improvements and structuralrefinements in elevator plugs, and the principal object of the inventionis to facilitate convenient and expeditious lifting and lowering ofsections of drill pipe.

This object is achieved by the provision of the instant plug which isadapted to be connected to an actuating line and which includes anexpansible and contractable body having an externally screw threadedlower end portion to engage the screw threads of a tool box or joint, animportant feature of the invention residing in the provision of meansfor rotatably connecting the plug to the actuating line so that thelatter may rotate without subjecting the plug to twisting or rotationsuch as would cause the screw threaded lower portion of its body tobecome disengaged from the tool joint.

Some of the advantages of the invention reside in its simplicity ofconstruction, in its convenient and expeditious operation as aforesaid,and in its ability to pull drill pipes without damaging the screw threadof the tool joint.

With the above more important objects and features in view and suchother objects and features as may become apparent as this specificationproceeds, the invention consists essentially of the arrangement andconstruction of parts as illustrated in the accompanying drawings, inwhich:

Figure 1 is an elevational view of the invention.

Figure 2 is a vertical sectional view of the invention per se.

Figure 3 is a transverse sectional view, taken substantially in theplane of the line 3-3 in Figure 2, and

Figure 4 is a transverse sectional view, taken substantially in theplane of the line 4-4 in Figure 2.

Like characters of reference are employed to designate like parts in thespecification and throughout the several views.

Referring now to the accompanying drawings in detail, the inventionconsists of an expansible elevator plug designated generally by thereference character It], the same embodying in its construction avertically disposed stem l2 which is provided at its upper end with adiametrically reduced portion l4 affording a shoulder IE to abut thelower surface of a yoke l8 connected to a suitable actuating line 20.

An end thrust bearing 22 is positioned on the diametrically reducedportion [4 of the stem l2,

2 and the portion l4 also carries a keeper nut 24 which engages thebearing 22 and thereby permits the yoke Hi to rotate without rotatingthe stem, while reducing the friction of rotation to a minimum.

A substantially tubular, expansible and contractable body 26 is slidablypositioned on the stem [2 and consists of a plurality of longitudinalsections '28, this body affording an axial bore which has a downwardlydivergent lower end por tion 30, as illustrated in Figure 2.

The lower end portion of the stem 12 is camsurfaced as at 32 and isoperatively positioned in the divergent portion 30 of the bore of thebody 26, so that when the stem 12 is slid upwardly in the body, thesections 28 of the body are expanded. Moreover, a compression spring 34is positioned on the stem l2 between the body 26 and the yoke I8, so asto assist the stem I: in urging the body to its expanded position.

The several body sections 28 are provided with recesses which define aplurality of annular grooves 36, 38, 40 in the outer surface of the body'26, the grooves 36, 38 accommodating a pair of keeper rings 42, 44respectively, which loosely embrace the body and thereby prevent thesections thereof from excessive spreading. The rings 42, 44, however,themselves are not expansible.

The groove 40 accommodates an annular spring 46 which is substantiallystronger than the spring 34 and thereby overcomes the resiliency of thelatter spring and urges the sections 28 of the body 26 to theircontracted positions, and finally, it is to be noted that the lower endportion of the outer surface of the body 26 is provided with screwthreads 48 for gripping purposes, as will be presently explained.

When the invention is placed in use, the plug Ill is lowered by means ofthe actuating line 20 until the screw threaded portion 48 of the body 26is received in an internally screw threaded joint or box 52 of a drillrod 54 which is to be elevated or lowered.

The body 26 is sufficiently heavy so that when the line 20 is pulledupwardly the body will tend to remain at rest, while the cam surfacedportion 32 of the stem l2 will expand the sections 28 of the body 26 infrictional engagement with the joint 52 and, consequently, as upwardpulling force is exerted upon the line 20, the entire plug together withthe drill rod 54 will be drawn upwardly.

Needless to say, the gripping action between the plug and the joint 52of the drill rod 54 3 is substantially enhanced by the provision of thescrew threads 48 on the body 26, which screw threads engage the screwthreads of the tool joint 52 and, without mutilating the tool joint,afford a positive connection between the plug and the drill rod or pipe54.

It is believed that the advantages and use of the invention will beclearly understood from the foregoing disclosure and accordingly,further description thereof at this point is deemed unnecessary.

While in the foregoing there has been shown and described the preferredembodiment of this invention, it is to be understood that minor changesin the details of construction and arrangement of parts may be resortedto without departing from the spirit and scope of the invention asclaimed.

Having described the invention, what is claimed as new is:

An elevator plug comprising an upright stem having a diametricallyreduced and screw threaded shank at its upper end, a frustoconical cammember provided at the lower end of said stem, a suspension yokerotatably mounted on said shank, a thrust bearing provided on the shankwithin said yoke, a keeper nut on the shank above said bearing, asubstantially tubular expansible and contractible body provided with anaxial bore having said stein slidable therein,

said bore including a frusto-conical lower end portion operativelyengaged by said cam member, a yieldable element positioned on said stembetween the upper end of said body and said yoke, said body beingprovided in its lateral surface with upper and lower annular grooves, anannular spring positioned in the lower groove for contracting the body,and a rigid keeper ring positioned in the upper groove for limiting theexpansion of the body, the inside diameter of said ring being greaterthan the diameter of the body in the plane of the upper groove when thebody is in its contracted position.

CLAUAST R. MURPHY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 695,169 North Mar. 11, 1902794,308 Noble July 11, 1905 1,418,538 Crutcher June 6, 1922 1,476,727Quigg Dec. 11,'1923 1,495,557 Kinley May 27, 1924 1,508,417 SpitlerSept. 16, 1924 1,519,445 Finney Dec. 16, 1924 1,525,520 Spitler Feb. 10,1925 1,825,026 Thomas Sept. 29, 1931 1,839,493 Nutter Jan. 5, 19321,897,561 Manucci et al. Feb. 14, 1933 2,105,885 Hinderliter Jan. 18,1938 2,261,564 Robichaux et al. Nov. 4, 1941 2,496,360 Stone Feb. 7,1950

